Aromatases are enzymes that synthesize estrogen from androgens, and aromatase inhibitors block this conversion. This lowers the estrogen level in a person treated with an aromatase inhibitor, slowing the growth of estrogen-responsive cancers, such as breast cancer and ovarian cancer, or providing other benefits of decreased androgen conversion to estrogen. Examples of aromatase inhibitors include exemestane, anastrozole, letrozole, vorozole, formestane and fadrozole.
Numerous therapeutic choices are available to clinicians for treatment of estrogen-responsive cancers and in other conditions where it is desirable to decrease estrogen produced in a subject. However, because of the expense and inconvenience to the subject of treatment with a drug which is ineffective in the subject, it is desirable to determine which drugs are or will be therapeutically effective in the subject.
Embodiments of the present invention provide methods for aiding in determining the therapeutic efficacy of an aromatase inhibitor in a subject.